1. Field of the Invention
The present invention relates to a base unit, a spindle motor, and a disk drive apparatus.
2. Description of the Related Art
Spindle motors arranged to rotate disks are installed in hard disk drives. A conventional hard disk drive and a conventional spindle motor are described, for example, in JP-A 2006-040423. Paragraph [0032] of JP-A 2006-040423 states that the spindle motor (SPM) is fixed to a base of a hard disk drive (HDD). In addition, paragraph [0065] of JP-A 2006-040423 states that a low-density gas having a lower density than that of air, such as He, is used as an atmosphere inside a hard disk assembly (HDA).
A flexible printed circuit board is arranged inside a hard disk drive. The flexible printed circuit board supplies drive currents to a spindle motor. The flexible printed circuit board is connected to an external power supply by a through hole defined in a base. However, a case of the hard disk drive needs to be airtight in order to keep an interior space thereof clean. Therefore, it is required to seal the through hole.
In a conventional hard disk drive, a connector of a flexible printed circuit board is arranged on an upper surface of a base including a through hole to seal the through hole. However, in the case where an interior of the case is filled with the low-density gas, such as He, which tends to easily pass through even a minute gap, as in JP-A 2006-040423, particularly high airtightness is required. Therefore, simply closing the through hole with the connector may fail to prevent a leakage of the low-density gas.
In order to prevent a leakage of the low-density gas out of the case, it is conceivable, for example, to arrange an adhesive between the connector and a periphery of the through hole. However, a variety of electrical wires are arranged around the connector. Electrical connection may be disturbed if the adhesive is brought into contact with these electrical wires and an electrode terminal of the connector.